We talk about vacuum leaks on this blog a lot. And for good reason! At least 90 percent of all evaporator performance problems can be traced back to vacuum leaks.           over-pressure relief valves

The potential causes of vacuum leaks are many, from cracks in older equipment to brittle and leaking seals. One preventable source of vacuum leaks is in over-pressure relief valves.

Many evaporators that operate under vacuum use relatively simple over-pressure relief valves to prevent positive pressure in the processing equipment. Many of these valves contain an elastomeric ball that seats against a conical metal surface to create an air-tight seal. When the balls sit in the same position for a long time (which they inevitably do), the balls become “indented” by the metal sealing surface. If/when these valves relieve, the ball often shifts position and seats differently, and the indentation prevents the ball from sealing completely, creating a vacuum leak.

To eliminate this issue, the balls can be rotated so that any indentation(s) are not contacting the sealing surface.

The pictures above and below were taken during a recent visit to a customer site to review their evaporator for potential issues.

If you would like us to perform an assessment of your evaporator, contact us by calling 410-822-6900 or by sending email to problem.solved@caloris.com to be connected with an engineer.